Method of distillation



No, 878,785. T A 'DUWAN FATENTED $1913.11, 1908.

. L METHOD OF DISTILLATION.

APPLICATION FILED JULY20,190 5.

I I g jf/wzna-S 0021/ 7 Q a,

THOMAS A. Dorcas, or CHICAGO, ILLINOIS.

METHOD OF DISTILLATION.

Specification of Letters Patent.

Patented Feb. 11, 1908.

pplication filed July 20. 1905. Serial No. 270.474.

To, all whom it may concern: "Be'itknown'that I, THOMAS A. Dtxeax, a citizeiiof the United States ofiAmeric-a, residing at Chicago, in the county of Cook, and State of'Illinois, have invented certain new and useful Improvements in a Method of Distillation, of which the following is a specification. 9 1 My invention relates to an improved method of distillation, the preferred form of :%pparatus which I use in practicing 'niy method being illustrated in the drawings furnished herewith, in which igure 1 is al'view 'of the apparatus partly in elevation, and partly in cross-section; and Fig. "21s a 'diagranmiatic iew partlyin sec- 'tion ofthe'hea'ting system and illustrating the method of raising the temperature in the retort from a certain constant degree oi temperature to one of a higher constant degree. The apparatus used in practicing my method consists preferably in a retort, A,

which mav be in the form of a tunnel adapted to be clos ed at'both'e'nds and hating inits upper end an eduction flue, a, communicating with a condensing worm, B,'-in which the Vapors are condensed and from'whicli the product may be run to suitable barrels or other receptacles. \Yithin the retort are rails, a u on which run cars, C. The wood to be distilled is piled upon these cars in a suitable manner and drawn into the retort and left there during the proc'essof distillation. In the bottom of the retort is an eduction pipe, a through which the heavier products are run away from the same.

D, re resents a system of pipes adapted to circu ate a heating medium, such as'hot air, steam, or other substance. These pi es run through a heater, E, which is adapte to maintain a certain constant predetermined degree of heat in the retort. the drawings, this heater contains a suitable material the melting or boiling point of I which is in a constant relation to the fixed temperature desired, so-that as long as the fire underneath this material is kept up and the material is kept at a; boiling or-melting point, the heat imparted to the fluid which circulates in the heatin system. will be constant at all times. Tln's heater therefore acts. as a heat'regulato'n' operating to maintain in the retort a constant predetermined de e of 'heat. During t e course of dist' ation I raise the tem era, ure'in the retort {from one constant pre etern ined degree to lat-ion therein at the initiation of the As shown in much; higherthan that in the other. As

shown in Fig; 2, the circulating pipe of theheating system branches at the point, (1, each branch of the pi 'e entering one of the heaters. A valve is ocated at this point whereby the passageway to either or both of said branches may beopened/ -'These pipes are brought together again where they return from the two heaters and are. here also provided with a similar valve. A fan or pump, D,'is interposed in the lieat-circulatmg pipes to cause free circulation therein."

F represents a nozzle extending from a.- steam-pipe, F through which steam may be injected into the retort to produce circuprocess of distillation.

' G represents a valved supply pipe through which the conducting medium may be sup- -T he temperature may then be raised to melt out the resin carrying the remaining turpentine, which remaining turpentine then distils from the resin. The "heat used, however, is not sufiicient to. break up any' art of the cellulose, and no part of the aci or tar of such distillation is carried over or melted out. In practice, I aim to maintain de rees F.

l n practicin my improved method, the cars are loaded up with resinous wood and run into the retort, the ends of which are then properly closed, and the cars allowed to remain in the retort from eight to twent four hours, depending upon the size of tie wood. If it is necessary, I introduce a jet of steam to cause freer circulation of air in the retort at the initiation ofthe process, but this is no part of-the distillation. The wood is then subjected to the influenceof radiated d1 heat at a constant temperature of say, 250 F.', until that portion of the tur- -constant temperatures between 250 and 450 pentine has been distilled which is carried oil with the included water. The temperature is then raised to say, 450 F. by opening the valves in the circulating pipes, so that heatcirculating fluid will pass through the second heater Where the temperature of the heatcirculating medium will be "raised to the hi her degree of temperature. The resin will now exude from the wood carrying with.

itthe remaining turpentine. This resin will collect in the bottom of the retort where it will be allowed to remain until all of the tur pentine has been distilled therefrom. The vapors rise to the dome of the retort and pass out through the eduction flue, a, into the worm, B, where they are condensed. hen the resin ,is melted out of the wood, and the distillation of turpentine completed, the rosin which remains in the bottom of the retort is drawn out through the eduction flue, (1. After all the'rosin and turpentine have been separated from the wood, the car is run out and another one run into the retort to take its place. I find that the wood atter ha-Vin been subjected to this process has not been estroyed. but is a commercial article of considerable value.

In the course of my experiments in this art, I have discovered that the most important factor in the process of distilling wood is to maintain one or more constant degrees of temperature in the retort and that withoutthis, successful commercial separation is al' most impossible. I have discovered that by assing thehea-t circulating pipes through a eat regulating device, such as the one described in this s iecification, the temperature in the retort will be kept constant. It is not suflicient that the regulation of the heat be left to an attendant because the best that he can do is to watch a )yrometer and when the temperature gets below the proper point, to increase the fire the effect of which will be to greatly increase the heat in the retort which will soon again fall below the one desired. In the course 01' my experiments this is exactly the diiiiculty attendant when no mechanicallr perfect regulation is employed.

\Yhilc l have shown and described my iniprovcd method of distilling as applied to the se ){tlfltiOIf-fOf gunrfroin resinous wood.

it is o vious that the same is applicable to the distillation oi materials other than wood.

I claim as new and desire to secure by Letters Patent 3 1 The method of distilling by means ot a medium circulating through a heating agent 01 such a nature that its superior possible temperature under ntmospl'icric pressure is adapted to impart to the circulating medium the temperature required for distilling the desired fraction.

2. The method of distilling resinous wood by means of a medium circulating through a heating agent of such a nature that its su perior possible temperature under atmospheric pressure is adapted to impart to the circulating medium the temperaturerequired for distilling the desired fraction.

In witness whereof I have signed the above application for Letters Patent at Chicago, in the county of (ooh and State of. Illinios, this 18th day of July, A. D. 1905.

THOMAS A. DUNGAX.

itnesses 1 CHAS. 0. Summer, K. W. (orixwALn 

